EP 0 581 491 A describes a water dispenser having a housing which supports an inverted bottle. A feed tube projects upwardly into the neck of the bottle through which water discharges under gravity into a reservoir in the form of a flexible bag. Water is chilled in the reservoir before being dispensed from a discharge outlet which incorporates a manually operable valve. For hygienic purposes the feed tube is incorporated in a unit which can be removed together with the bag and the associated tubing for replacement during a maintenance operation.
Whilst most bottled water dispensers provide still (ungassed) water there is a growing demand for water which has been oxygenated. Drinking water with an increased level of dissolved oxygen is believed by some to provide health benefits and generally enhance body functions.
Known oxygenating water coolers have a fixed reservoir in which oxygen is bubbled through the water. The reservoir must be of a considerable size in order to maximise the contact area between the oxygen bubbles and the water, and the reservoir is prone to bacterial contamination. Such oxygenating techniques require a large amount of oxygen which is usually supplied from an in-built oxygen generator, which further increases the size and complexity of the apparatus. Furthermore, the dispensed water does effervesce very freely so that it has the appearance of being flat compared with fizzy carbonated drinks with which most people are familiar.
The present invention seeks to provide a new and inventive form of gassed liquid dispenser which is hygienic to use, is relatively small and compact, and offers efficient use of gas whilst providing a highly effervescent or fizzy product.